Flow behaviour of akamu from different maize varieties and fortified with soybean flour

• Published in: Food control 1997-04, Vol.8 (2), p.105-111
• Main Authors: Abubakar, Usman M., Sopade, Peter A., Yelmi, Bitrus M.
• Format: Article
• Language: English
• Subjects: power-law equation; pseudoplastic; rheology; soy-ogi; viscosity
• ISSN: 0956-7135; 1873-7129
• DOI: 10.1016/S0956-7135(97)00002-9

Akamu, made from four maize varieties, (YNCV, FARZ-24, WFV, and YFV) and fortified (0–40%) with soybean, was studied to obtain its rheological properties at temperatures that ranged from 10 to 70 °C. Four rotational speeds (10, 20, 50 and 100 rev min −1) were used and the viscosity-speed data were analysed by an empirical power-law equation. Irrespective of the maize varieties, level of fortification and temperature, viscosity reduced with rotational speed. The empirical power-law index suggested a pseudoplastic behaviour that was independent of the variables studied unlike the consistency index. YNCV and FARZ-24 produced a more viscous akamu although akamu samples from WFV and YFV were more sensitive to temperature. Soy-akamu was less viscous but more sensitive to temperature. The relationship between the consistency index ( K), and absolute temperature ( T) and level of fortification ( S) was described by an exponential equation of the form: K = 4.32 × 10 −2exp {11.9 × 10 6/( R/ T) − 2.74 × 10 −2 S} r 2 = 0.8584